Structure and microwave dielectric properties of La(Mg0.5Ti0.5)O3-CaTiO3 system

• Published in: Journal of the European Ceramic Society Vol. 23; no. 14; pp. 2403 - 2408
• Main Authors: SEABRA, M. P, AVDEEV, M, FERREIRA, V. M, PULLAR, R. C, ALFORD, N. Mcn
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Elsevier 2003
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electrotechnical and electronic ceramics; Exact sciences and technology; Permittivity (dielectric function); Physics; Technical ceramics; Perovskite type compound; Property composition relationship; Binary system; Microwave; Composition effect; Oxide ceramics; Powder; Structure composition relationship; Dielectric ceramics; Lanthanum oxide; Lanthanide compound; Chemical preparation; Manufacturing; Magnesium Oxides; Electroceramics; Magnesium Lanthanum Titanium Oxides Mixed; Q factor; Electrical properties; Dielectric properties; Calcium Titanates; Experimental study; X ray diffraction; Titanium Oxides; Microstructure; Crystalline structure
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(03)00142-0

(1-x)La(Mg0.5Ti0.5)O3 (LMT)-xCaTiO3 (CT) [0 < x < 1] ceramics were prepared from powder obtained by a nonconventional chemical route based on the Pechini method. The crystal structure of the microwave dielectric ceramics has been refined by Rietveld method using X-ray powder diffraction data. LMT and CT were found to form a solid solution over the whole compositional range. The 0.9LMT-0.1CT composition was refined using P21/n space group, which allows taking into account B-site ordering. The compounds having x# > 0.3 were found to be disordered and were refined using Pbnm space group. Microstructure evolution was also analysed. Dielectric characterization at microwave frequencies was performed on the LMT-CT ceramics. The permittivity and the temperature coefficient of resonant frequency of the solid solutions showed a non-linear variation with composition. The quality factor demonstrates a considerable decrease with the increase of CT content.